I. Field of the Invention
This invention relates generally to the field of mobile telephones, and more specifically pertains to a voice activated call answerer and a method for hands-free voice activation of a mobile telephone by verbal command.
II. Description of Related Art
When a mobile telephone is turned on in a cellular PCS radiotelephone environment, it typically must search for and acquire the forward link signal (pilot signal), which is continuously transmitted by a base station. The pilot signal is used by the mobile telephone to obtain initial system synchronization and to provide time, frequency and phase tracking of the signals from the base station. Since the mobile telephone cannot start transmitting or receiving until the pilot signal is acquired, this signal must be acquired quickly after the turn on, since the user typically does not want to wait to make a telephone call.
Once the mobile telephone is turned on, it may be used in a vehicle to send or receive telephone calls. In order to allow a driver, who wants to use the mobile telephone, to practice careful driving and pay good attention to the road environment, the mobile telephone is preferably placed in a carkit cradle mounted within the vehicle. Presently, however, answering an analog or digital mobile telephone call has to be started by manually pressing a key on a mobile telephone keypad. There does not appear to be a reliable method and architecture for activation of a mobile telephone by verbal command.
Therefore, there is a need for an efficient voice activated call answerer architecture and a method for hands-free voice activation of a mobile telephone by verbal command.
The preceding and other shortcomings of currently available mobile phone answering systems are addressed and overcome by the various embodiments of the present invention.
One embodiment of the present invention is a mobile telephone system for answering a mobile telephone incoming call by a user""s verbal command, to allow hands-free voice activation. The mobile telephone system includes a carkit and a mobile telephone. The mobile telephone has a programming key for pre-programming the user""s voice greeting, a keypad for answering the call in xe2x80x9ctelephone modexe2x80x9d, a microphone for entering a user""s verbal command for answering the call in xe2x80x9ccarkit modexe2x80x9d, a digital processor connected to the microphone for performing spectrum analysis and feature extractions of the user""s verbal command in carkit mode, and a memory connected to the digital processor, having a database for storing the digitized speech pattern of the user""s pre-programmed voice greeting.
The pre-programmed voice greeting may be a factory-programmedvoice greeting or the user""s pre-programmed voice greeting, if previously initialized by the user pressing the programming key. The digital processor performs spectrum analysis and feature extractions of the user""s verbal command for determining if a match exists between the user""s verbal command and the stored user entered pre-programmed voice greetings. If a match is found the digital processor also checks whether the user""s verbal command reaches a pre-programmed pass/fail voice threshold level.
Another embodiment of the present invention is a method for allowing a mobile telephone user to answer an incoming call by a verbal command to perform hands-free voice activation. The method may include performing initialization to pre-program a user""s voice greeting. If an incoming call is received, the method allows answering the incoming call by a verbal command, to accept or reject the incoming call.
The initialization step prompts and inputs the user""s voice greeting, prompts the user and enters a mobile telephone memory database location for storing the voice greeting, and stores the voice greeting represented as a digitized speech pattern in the specified mobile telephone memory database location. The digitized speech pattern may be in compressed or uncompressed form.
When a mobile device is paged to complete a voice call, it goes through the xe2x80x9ccall answeringxe2x80x9d process. The call answering process alerts the user to enter a verbal command, and waits for the user""s verbal command. If the user answers by a verbal command and if not previously initialized, the method outputs a factory-programmed voice greeting. If the user answers by the verbal command and if previously initialized, the method determines if a match is found of the user""s verbal command and the stored user pre-programmed voice greetings, and if a match is found, outputs the matched user preprogrammed voice greeting. After one of the voice greetings is output, the method sends a page response message to the mobile telephone""s base station to continue with the incoming call.
The foregoing and additional features and advantages of the present invention will become further apparent from the following detailed description and accompanying drawing figures that follow. In the figures and written description, numerals indicate the various features of the invention, like numerals referring to like features throughout.